Ray Waller, a baseball star forced into early retirement by a degenerative disease, moves into a new home with his wife Eve, teenage daughter Izzy, and young son Elliot. Secretly hoping to recover and return to professional sports, Ray convinces Eve that the fabulous pool in the backyard of their new home will be fun for the kids and will serve as physical therapy. But a dark secret from the house’s past will unleash a malevolent force that will drag the entire family into the unfathomable depths of the most suffocating terror.